Process for the preparation of styrene derivatives extended at the double bond by ethylene and having a double bond remaining in the extension chain formed and new styrene derivatives extended with ethylene

ABSTRACT

The title compounds can be prepared by reaction of a styrene derivative with ethylene in the presence of a nickel catalyst which carries a phosphorus-oxygen chelate ligand, at a temperature of 20° to 160° C. and an ethylene pressure of 1 to 200 bar. Styrene derivatives extended with ethylene, of the formula                    
     in which 
     R 19  denotes hydrogen, C 1 -C 4 -alkyl, vinyl or chlorine and 
     R 38  denotes C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl, C 2 -C 7 -acyl, flourine, chlorine or bromine and 
     m assumes values of 4-104, 
     with the exception of compounds wherein R 19  denotes hydrogen and R 38  denotes i-butyl or benzoyl, and m assumes the value 4, are new.

This application is a continuation of application Ser. No. 08/145,377,filed Oct. 29, 1993, now abandoned, which is a division of Ser. No.08/084,379, filed Jun. 29, 1993, which is an allowed reissue 34,706 ofSer. No. 07/704,751, filed May 23, 1991, now U.S. Pat. No. 5,180,872.

BACKGROUND OF THE INVENTION

The invention relates to a process for the reaction of styrenederivatives with ethylene in the presence of a nickel catalyst whichcarries a phosphorus-oxygen chelate ligand, styrene derivatives beingobtained which are extended with ethylene at the olefinic double bondand in which a double bond remains in the extension chain formed.

Such styrene derivatives extended with ethylene are interestingintermediates which, owing to the double bond remaining in the extensionchain, are suitable as precursors for graft polymers, for example withmethyl methacrylate or maleic anhydride, or polymer-analogous reactionscan be carried out using them. The styrene derivative employed accordingto the invention can moreover carry the substituents mentioned furtherbelow, which make possible other reactions or introduce other propertiesinto a polymer. Of particular interest are products obtainable accordingto the invention in which the styrene derivative carries a further vinylgroup, i.e. is, for example, divinylbenzene. In this case, mainly onlyone vinyl group is extended. The extended styrene derivatives formed inthe course of this are bifunctional; they carry two olefinic doublebonds of different reactivity. The unextended vinyl group can then beutilised in a manner known per se for styrene-analogous homo- orcopolymerisations. The polymers produced therefrom furthermore carrytheir poly(oligo)ethylene side chains from the extension according tothe invention bonded via the aromatic compounds and are thuspoly(oligo)ethylene-modified. Graft reactions, derivatisations,cross-linkings and other reactions can then be carried out on the doublebonds of these side chains.

SUMMARY OF THE INVENTION

A process for the preparation of styrene derivatives extended at thedouble bond with ethylene and having a double bond remaining in theextension chain formed has been found, which is characterised in that astyrene derivative is reacted with ethylene in the presence of a nickelcatalyst which carries a phosphorus-oxygen chelate ligand, at atemperature of 20° to 160° C. and an ethylene pressure of 1 to 200 bar.

DETAILED DESCRIPTION OF THE INVENTION

A relatively large number of nickel catalysts which carry aphosphorus-oxygen chelate ligand and which can be employed according tothe invention are known to the person skilled in the art.

Preferentially, the reaction is carried out in the presence of a nickelcatalyst which can be prepared by reaction of a nickel(O) compound, or acompound which can be converted in situ to a nickel(O) compound, with aphosphorus compound of the formula

in which

R⁴, R⁵, R⁶, R⁷ and R⁸ independently of one another denote straight-chainor branched C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₁-C₂₀-alkoxy,C₃-C₈-cycloalkyl, C₆-C₁₂-aryl, C₆-C₁₂-aryloxy, C₇-C₁₅-aralkyl orC₇-C₁₅-aralkoxy, where

R⁷ can additionally denote hydrogen and

R⁸ can additionally denote hydrogen, acyl or sulphonate

or nickel catalysts which can be prepared by reaction of a nickel(O)compound, or a compound which can be converted in situ to a nickel(O)compound, with an adduct of a quinoid compound or maleic anhydride and aphosphine of the formula

in which

R⁴, R⁵ and R⁶ have the meaning mentioned.

Such phosphorus ylide-nickel compounds can be employed both individuallyand as a mixture of several of them.

Preferentially, R⁴ has the meaning of optionally substitutedC₆-C₁₂-aryl. Additionally preferentially, in the preparation of theabove catalysts from a nickel(O) compound or a compound which can beconverted in situ to a nickel(O) compound, a compound of the formula (I)and additionally a compound of the formula

are used as starting compounds, in which

R¹, R² and R³ independently of one another denote straight-chain orbranched C₁-C₂₀-alkyl, C₁-C₂₀-alkoxy, C₃-C₈-cycloalkyl, C₂-C₂₀-alkenyl,di-(C₁-C₄-alkyl)amino, C₆-C₁₂-aryl, C₆-C₁₂-aryloxy, C₇-C₁₅-aralkyl orC₇-C₁₅-aralkoxy,

X denotes doubly bonded oxygen, the doubly bonded group NR⁹ or thedoubly bonded group

 R⁹ and R¹⁰ independently of one another denote hydrogen, silyl, acyl,chlorophenyl, nitrophenyl, C₁-C₆-alkylphenyl, cyano,phenyl-C₂-C₆-alkenyl or R¹, and

n assumes the value zero or one.

In the preparation of the above catalysts, starting from a nickel(O)compound, or a compound which can be converted in situ to a nickel(O)compound, and an adduct of a quinoid compound or maleic anhydride and acompound of the formula (II), it is additionally still preferred tostart from a compound of the formula (III).

Particularly preferentially, the reaction is carried out in the presenceof a nickel catalyst which is obtained by reaction of a nickel(O)compound with phosphorus compounds of the formulae

in which

R¹¹, R¹² and R¹³ independently of one another denote C₁-C₈-alkyl, phenylor benzyl,

R¹⁴ represents hydrogen, C₁-C₈-alkyl or phenyl,

R¹⁵, R¹⁶ and R¹⁷ independently of one another denote C₁-C₈-alkyl orphenyl, where R¹⁷ can additionally denote hydrogen or acyl, and

R²⁰ denotes phenyl or C₁-C₄-alkyl,

or a nickel catalyst which can be prepared by reaction of a nickel(O)compound, or a compound which can be converted in situ into a nickel(O)compound, with an adduct of benzoquinone or maleic anhydride and aphosphine of the formula

in which

R¹⁵ and R¹⁶ have the meaning mentioned,

and a compound of the formula (IV).

R²⁰ is preferentially phenyl.

0 to 4 mol of the compound of the formula (III) and 1 to 4 mol of thecompound of the formula (I) are employed per mole of nickel(O) compoundto prepare the catalyst, preferably about 1 mol of the compound of theformula (III) or (IV) and about 1 mol of the compound of the formula (I)or (V) per mol of the nickel(O) compound. Identical molar ratios applyif a compound of the formula (I) or (V) is replaced by aquinone/phosphine adduct or a maleic anhydride/phosphine adduct of thetype described.

The temperature for the preparation of the catalyst is 0° to 100° C.,preferably 20° to 70° C. The preparation is carried out with theexclusion of oxygen, preferably in a solvent, which must be inert to thereactants, such as benzene, toluene, cyclohexane or n-hexane. After itspreparation, the catalyst is usually isolated as a solid by filtering,the solution being concentrated and/or cooled beforehand as required.However, the catalyst can also be employed directly without isolation,i.e. as a solution or suspension, for the reaction according to theinvention.

Nickel(O) compounds which may be mentioned by way of example areNi(cyclooctadiene)₂ and Ni(allyl)₂. Examples of nickel compounds whichcan be converted in situ to nickel(O) compounds are: Ni acetylacetonate,Ni octanoate and Ni stearate, which can be reduced with the aid ofcustomary reducing agents, such as borohydride, alumino-hydride,aluminium alkyl or organolithium compounds.

Examples of alkyl, preferably C₁-C₈-alkyl, which can be straight-chainor branched are: methyl, ethyl, propyl, isopropyl, butyl, isobutyl,tert-butyl, the isomeric pentyls, hexyls, octyls, decyls, dodecyls,hexadecyls and eicosyls. Particularly preferred alkyl has 1 to 4C atoms.

Examples of C₁-C₂₀-alkoxy which can be straight-chain or branched are:methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert.-butoxy,the isomeric pentyloxys, hexyloxys, octyloxys, decyloxys, dodecyloxysand eicosyloxys. Preferred alkoxy has 1 to 8C atoms, particularlypreferred alkoxy 1 to 4C atoms.

Examples of C₃-C₈-cycloalkyl are: cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, methyl cyclopentyl, methyl cyclohexyl, cycloheptyl,cyclooctyl.

Examples of C₆-C₁₂-aryl are: phenyl, naphthyl, biphenylyl. Preferredaryl is phenyl.

Examples of C₂-C₂₀ alkenyl are: vinyl, propenyl, allyl, butenyl,pentenyl, hexenyl, octenyl, decenyl or eicosenyl and their branchedisomers.

Examples of C₆-C₁₂-aryloxy are: phenoxy, naphthyloxy, biphenyloxy.Phenoxy is preferred.

Examples of C₇-C₁₅-aralkyl are: benzyl, phenylethyl, phenylpropyl,naphthyl-methyl, preferably benzyl.

Examples of C₇-C₁₅-aralkoxy are: benzyloxy, phenylethyloxy,phenyl-propyloxy, naphthyl-methyloxy, preferably benzyloxy.

Examples of di-(C₁-C₄-alkyl)-amino are: dimethylamino, diethylamino,dipropylamino, methylbutylamino, ethylbutylamino etc.

Examples of silyl are tri-C₁-C₄-alkylsilyl, triphenylsilyl or mixedtrisubstituted alkylphenyl-silyls, preferably tri-C₁-C₄-alkyl-silyls,such as trimethylsilyl, triethylsilyl etc.

Acyl is C₁-C₈-alkylcarbonyl or C₆-C₁₂-arylcarbonyl which can besubstituted in the manner mentioned below, such as acetyl, propionyl,butyryl, C₅-alkyl-carbonyl, C₈-alkylcarbonyl, benzoyl, substitutedbenzoyl or naphthylcarbonyl. Preferred acyl is substituted orunsubstituted C₁-C₄-alkyl-carbonyl or benzoyl. Acetyl or benzoyl areparticularly preferred.

The said substituents can be monosubstituted to trisubstituted,preferably monosubstituted or disubstituted, particularly preferablymonosubstituted, by C₁-C₄-alkyl, by C₁-C₄-alkoxy, by C₆-C₁₂-aryl, or byC₆-C₁₂-aryloxy or nitro, preferably by C₁-C₄-alkyl, by C₁-C₄-alkoxy, orby phenyl or phenoxy, it being possible in the case of multiplesubstitution for the substituents to be different from the saidenumeration. In this sense, tolyl, for example, is additionallyunderstood as aryl.

Suitable quinoid compounds are o- or p-quinoid compounds of the benzeneand naphthalene series and also anthraquinones, which can additionallybe substituted in the manner described above. p-Benzoquinone,1,4-naphthoquinone and 9,10-anthraquinone may be mentioned by way ofexample.

The preferred nickel compounds containing phosphorus-oxygen chelateligands are, according to present knowledge, in agreement with theformula

in which

X, n and R¹ to R⁸ have the meanings mentioned above.

In the case in which a compound of the formula (I) is replaced, forexample, by a maleic anhydride/phosphine adduct of the type described,the formula (VII) becomes the formula below

A general structural feature of the nickel catalysts which can beemployed according to the invention and which carry a phosphorus-oxygenchelate ligand is the following configuration

Preferred radicals R¹, R² and R³ are C₁-C₈-alkyl, cyclohexyl, phenyl,tolyl, benzyl, di-(C₁-C₄-alkyl)-amino, phenoxy and C₁-C₄-alkoxy.

R⁴ is preferably C₆-C₁₂-aryl, particularly preferably phenyl.

R⁵, R⁶, R⁷ and R⁸ are independently of one another preferablycyclohexyl, phenyl, tolyl, benzyl, vinyl and C₁-C₄-alkyl.

R⁷ is moreover preferably hydrogen or C₁-C₄-alkoxy, R⁸ is moreoverpreferably hydrogen, acetyl, benzoyl or the sulphonate group.

R⁹ and R¹⁰ are preferably hydrogen, C₁-C₈-alkyl, phenyl, chlorophenyl,nitrophenyl, C₁-C₆-alkylphenyl, trimethylsilyl, cyano, C₂-C₆-alkenyl andphenyl-C₂-C₆-alkenyl.

0.01 to 100 mmol of nickel catalyst per mol of styrene derivative,preferably 0.1 to 10 mmol of nickel catalyst, particularly preferably0.2 to 5 mmol of nickel catalyst, are employed for the reactionaccording to the invention. It is furthermore possible to activate thesenickel catalysts by organoaluminium compounds, preferably alkyl- oralkoxy-aluminiu compounds.

The process according to the invention is carried out at a temperatureof 20° to 160° C., preferably at 30° to 140° C., particularly preferablyat 40° to 120° C., very particularly preferably at 50° to 100° C.

It is carried out at an ethylene pressure of 1 to 200 bar, preferably 2to 50 bar, particularly preferably 3 to 25 bar.

According to the invention, a styrene derivative of the formula

is employed in which

R¹⁸ is hydrogen, C₁-C₄-alkyl, C₂-C₄-alkenyl, C₂-C₇-acyl, fluorine,chlorine or bromine and

R¹⁹ is hydrogen, C₁-C₄-alkyl, vinyl or chlorine.

Examples of C₂-C₇-acyl are; acetyl, propionyl, butyryl, benzoyl,preferably benzoyl.

Preferentially, styrene derivatives of the formula

are employed in which

R²⁸ is hydrogen, methyl, ethyl, i-butyl, C₂-C₇-acyl, vinyl or chlorineand

R²⁹ is hydrogen, vinyl, methyl or chlorine.

Particularly preferentially, styrene or divinylbenzene are employed.

The styrene derivatives to be employed according to the invention can beemployed both in pure form and as a technical mixture. An importantexample of this latter case is technical divinylbenzene, whichadditionally contains ethyl-styrene and; or diethyl-benzene. Furtherbenzoyl styrenes, e.g. 3-benzoyl styrene, can be mentioned.

The process according to the invention is Carried out in the liquidphase. In this case, the reaction can basically be carried out withoutco-use of an inert solvent if the styrene derivative is liquid.

In many cases, the process according to the invention is carried out inthe presence of an inert solvent. Suitable examples of such inertsolvents are: n-hexane, cyclohexane, petroleum ether, ligroin, benzene,toluene, chlorobenzene, acetone, dimethylformamide and other solventswhich are not attacked under the reaction conditions, preferablycyclohexane or toluene.

The inert solvent is employed in an amount by weight which is 0.1 to 100times, preferably 0.5 to 20 times, relative to the styrene derivative.

The reaction product of the process according to the invention is ingeneral initially a homologous series of extended styrene derivatives inwhich the extension comprises one molecule of ethylene per molecule ofthe basic styrene derivative or two or more molecules of ethylene permol of the basic styrene derivative and in which a double bond remainsin the extension chain. The individual components of thestyrene-ethylene reaction can be represented by the following formulae:

Formula (XIa) in this connection represents the case styrene/ethylene=1:1, formula (XIb) represents the case styrene/ethylene =1:2, andformula (XIc) represents the general case styrene/ethylene =1:1 +n,where n principally assumes values from 0 (zero) to 100, in particular 0to 30, very particularly 0-10.

As a result of isomerisation reactions, homologous series of isomericproducts are also formed in the process according to the invention,which appear to be in agreement with the following formulae:

With olefinically unsaturated compounds, owing to the cis-transisomerism known to the person skilled in the art, the corresponding cisisomers always also occur in addition to the above compounds of theformulae (XI) to (XVII) (XVI) represented as trans isomers.

In the formulae (XI a-c), (XII a and b) and (XIII) to (XVII), thebending points and end points of the bent line (=extension chain)denote, in a manner familiar to the person skilled in the art, C atomswhich have the necessary number of H atoms. As a result, for example,the following detailed notation results for the formulae (XIa) and(XIII)

In the formulae (XI) to (XVII), the ring substitution as in formula (IX)or (X) has been left out for the sake of clarity.

The whole of the process product of the process according to theinvention having a double bond remaining in the branched or unbranchedextension chain can thus be represented by the formula

in which the index m assumes the value of the above index n+4 2n+4 andR¹⁸ and R¹⁹ have the above scope of meaning.

In the manner shown above, this is in general the mixture of thehomologues coming under the formula (XVII).

Polyolefins occur as by-products.

Such a product mixture can be separated into individual components orinto fractions in a manner known to the person skilled in the art, forexample by chromatographic separation, fractional distillation orprecipitation.

The process according to the invention is surprising insofar as usingthe nickel catalyst to be employed, with which, as is known, ethylenecan be polymerised, polyethylene formation in this case now becomes theside reaction. Polystyrene formation is also almost completelysuppressed. The homologous series of styrene/ethylene coupling productsbecomes the principal reaction product, a shift to higher or lowermolecular weights taking place according to the methods known forpolyethylene molecular weight control. Molecular weights below 10,000g/mol are preferred, particularly preferably below 1,000 g/mol.

The following procedures, for example, are suitable for the processaccording to the invention:

a) initial introduction of the solid, suspended or dissolved catalyst(or its components) and addition of the monomers simultaneously orsuccessively at the desired temperature;

b) initial introduction of the monomers and injection of the catalystsolution or suspension (or its components) at the desired temperature,if appropriate with subsequent heating;

c) continuous metering of the catalyst solution (or its components) andthe monomers under prestated desired polymerisation conditions(pressure, temperature).

The process according to the invention can be carried out, for example,as follows: the solvent is initially introduced into an autoclave. Theintended amount of styrene derivative is then added. Ethylene, on itsown or mixed with an inert gas, is then pumped into the closed autoclaveto the desired reaction pressure, if appropriate taking into account thepressure increase at reaction temperature. The autoclave is then heatedto the desired reaction temperature and the nickel catalyst is added asa solid, as a suspension or as a solution. Preferably, a catalystsolution is pumped in simultaneously to the use of ethylene (multi-pulseprocess). The carrying-out of the polymerising coupling of the styreneis assisted by shaking of the autoclave or by a suitable lifting orstirring device. The ethylene can be replenished at the rate of itsconsumption during the reaction. After completion of the reaction, theautoclave is cooled, depressurised and opened. The reaction mixture isworked up, for example, by distillation. In this case, the optionallyco-used inert solvent and the unreacted styrene derivative are separatedoff first, for example by distillation. The remaining reaction mixturecontaining the extended styrene derivatives prepared according to theinvention can then be separated into individual components or intosuitable fractions by fine distillation, by crystallisation orprecipitation or by other separating operations. All distillations areadvantageously carried out in the presence of customary stabilisers inorder to suppress thermal polymerisation.

A number of styrene derivatives extended with ethylene, which can beprepared according to the invention and which have a remaining doublebond in the extension chain formed, are new.

The invention therefore furthermore relates to styrene derivativesextended with ethylene, of the formula

in which

R³⁸ represents C₁-C₄-alkyl, C₂-C₄-alkenyl, C₂-C₇-acyl, fluorine,chlorine or bromine,

R¹⁹ has the above scope of meaning and

m assumes values of 4 to 104 204, preferably 4 to 34 6 to 64,particularly preferably 4 to 14 6 to 24,

preferably those of the formula

in which

R⁴⁸ denotes vinyl, i-butyl or benzoyl and

R²⁹ and m have the above scope of meaning,

particularly preferably those of the formula

in which R⁴⁸ and m have the above scope of meaning, whereby compoundsare excepted wherein R¹⁹ and R²⁹, respectively, denote hydrogen, R³⁸ andR⁴⁸, respectively, denote i-butyl or benzoyl, and m assumes the value 4.

This means in the case of formula (XX) that m assumes values of 6 to 104204, preferably 6 to 34 64, particularly preferable 6 to 14 preferably 6to 24, taking into account that the difference in the lower limit of m(6 instead of 4) makes just one ethylene (C₂) unit.

Of course, the new styrene derivatives extended with ethylene, of theformulae (XVIII), (XIX), and (XX) also include the mixture of thehomologous series formed from them.

The new substances mentioned likewise also include the mixture with thetechnical impurities of the basic styrenes and/or with the homologousreaction products extended with ethylene in the case in which styrenederivatives present in technical purity have been used as startingmaterials; this case has been illustrated further above for technicaldivinylbenzene.

EXAMPLE 1 Catalyst preparation [NiPh(Ph₂PCHCMeO)(Pr^(i) ₃PCHPh)]

40 mmol of bis-cyclooctadiene-nickel(O) in 250 ml of dry argon-saturatedtoluene were mixed under argon with 40 mmol ofacetylmethylene-triphenylphosphorane and 40 mmol oftriisopropyl-phosphinebenzylidene. The mixture was heated to 60° C. forabout 3 hours with intensive stirring. The dark brown reaction mixturewas filtered under argon and the filtrate was concentrated to dryness invacuo. The crude catalyst thus obtained was dissolved in toluene at 60°C., hexane was added until turbidity persisted and the solution wascrystallised in the cold, the crystals were isolated by Schlenkfiltration, washed with hexane and dried in vacuo.

EXAMPLES 2-10 General experimental procedure

The amount of toluene mentioned in the following tables, the amount ofcatalyst mentioned and the amount of styrene derivative mentioned wereinitially introduced into an autoclave of suitable size. An amount ofethylene was then added under pressure such that the ethylene pressureindicated in the tables was attained at the reaction temperatureindicated. During the reaction period indicated in the tables, ethylenewas additionally added to maintain the pressure indicated. The yield wasdetermined by weighing the residue after distillative separation ofsolvent and unreacted styrene derivative. The tables show the resultsobtained by gas chromatography relating to the percentage distributionof extended styrene derivatives (denoted as “product”) and co-formedα-olefin (polyethylene by-product).

TABLE 1 (Examples 2 to 5) Reaction of styrene derivatives in toluenewith ethylene at a temperature of 80-90° C. in a 2-hour reactionCatalyst Styrene Ethylene Toluene Yield Product α-olefin No. Type Amountderivative bar ml g % % 2 NiPh(Ph₂PCHCMeO) 1 mmol 0.1 mol 10 80 not 6040 (Pr^(i) ₃PCHPh) p-methyl- deter- styrene mined 3 NiPh(Ph₂PCHCMeO 1mmol 0.1 mol 10 80 not 50 50 (Pr^(i) ₃PCHPh) 3,4-dichloro- deter-styrene mined 4 Ni(COD)₂ 4 mmol 1 mol 5 500  35 71 29 Ph₃PCHCPhOo-chlorostyrene Ph₃PO 5 Ni(COD)₂ 4 mmol 3 mol 5 500 220 74 26 Ph₃PCHCPhOstyrene Ph₃PO

TABLE 2 (Examples 6 and 7) Reaction of divinylbenzene (DVB, freshlydistilled, 390 g in each case) in toluene (1,000 ml in each case) withethylene in a 2-hour reaction; catalyst metering by multi-pulse CatalystEthylene Temp. Yield Product α-olefin No. Type Amount bar ° C. g % % 6Ni(COD)₂ 4 mmol in 2.5 90 173 89 11 Ph₃PCHCPhO situ in Ph₃PO 150 mltoluene 7 NiPh(Ph₂PCHCPhO) 4 mmol 5.0 50 278 85 15 (Ph₃P) isolated in150 ml toluene for the catalyst: COD = cyclooctadiene; Ph = phenyl; Me =methyl Product = Total amount of the extended styrene derivativeobtained

TABLE 3 (Examples 8 to 10) Reaction of divinylbenzene (DVB, freshlydistilled, 390 g in each case) in toluene (1,000 ml in each case) withethylene at 90° C. in a 2-hour reaction with 4 mmol ofNi(COD)₂/Ph₃PCHCPhO/Ph₃PNSiMe₃ as an in situ catalyst in 150 ml oftoluene, catalyst metering: multi-pulse Ethylene Yield Product α-olefinNo. bar g % %  8 10 320 70 30  9 5 345 83 17 10 2.5 110 91 9

What is claimed is:
 1. A process for the preparation of styrenederivatives extended at the double bond with ethylene and having adouble bond remaining in the extension chain formed, according to theformula

in which R¹⁹ denotes hydrogen, C₁-C₄-alkylvinyl or chlorine, R³⁸ denotesC₁-C₄-alkyl, C₂-C₄-alkenyl, C₂-C₇-acyl, fluorine chlorine or bromine,and m has a value of 4 to 104, with the exception of compounds whereinR¹⁹ is hydrogen and R³⁸ is isobutyl or benzyl and m has the value 4,wherein a styrene derivative is reacted with ethylene in the presence ofa nickel catalyst which carries a phosphorus-oxygen chelate ligand, at atemperature of 20 to 160° C. and an ethylene pressure of 1 to 200 bar,wherein the nickel catalyst is obtained by reaction of a nickel (O)compound, or a compound which can be converted in situ to a nickel (O)compound, with a phosphorus compound of the formula

in which R⁴, R⁵, R⁶, R⁷ and R⁸ independently of one another denotestraight-chain or branched C₁-C₂₀-alkyl, C₂-C₂₀-alkenyl, C₁-C₂₀-alkoxy,C₃-C₈-cycloalkyl, C₆-C₁₂-aryl, C₆-C₁₂-aryloxy, C₇-C₁₅-aralkyl orC₇-C₁₅-aralkoxy, where R⁷ can additionally denote hydrogen and R⁸ canadditionally denote hydrogen, acyl or sulphonate, or a nickel catalystwhich can be prepared by reaction of a nickel (O) compound, or acompound which can be converted in situ to a nickel (O) compound, withan adduct of a quinoid compound or maleic anhydride and a phosphine ofthe formula

in which R⁴, R⁵ and R⁶ have the meaning mentioned.
 2. The process ofclaim 1, wherein for the preparation of the nickel catalyst from anickel(O) compound or a compound which can be converted in situ into anickel(O) compound, and from a compound of the formula (I) or from anadduct of a quinoid compound or maleic anhydride and a compound of theformula (II), a compound of the formula

in additionally used as a starting material in which R¹, R² and R³independently of one another denote straight-chain or branchedC₁-C₂₀-alkyl, C₁-C₂₀-alkoxy, C₃-C₈-cycloalkyl, C₂-C₂₀-alkenyl,di-(C₁-C₄-alkyl)amino, C₆-C₁₂-aryl, C₆-C₁₂-aryloxy, C₇-C₁₅-aralkyl orC₇-C₁₅-aralkoxy, X denotes doubly bonded oxygen, the doubly bonded groupNR⁹ or the doubly bonded group

R⁹ and R¹⁰ independently of one another denote hydrogen, silyl, acyl,chlorophenyl, nitrophenyl, C₁-C₆-alkylphenyl, cyano,phenyl-C₂-C₆-alkenyl or R¹, and n assumes the value zero or one.
 3. Theprocess of claim 3, wherein the reaction is carried out in the presenceof a nickel catalyst which is obtained by reaction of a nickel(O)compound, or a compound which can be converted into a nickel(O) compoundin situ, with phosphorus compounds of the formulae

in which R¹¹, R¹² and R¹³ independently of one another denoteC₁-C₈-alkyl, phenyl or benzyl, R¹⁴ represents hydrogen, C₁-C₈-alkyl orphenyl, R¹⁵, R¹⁶ and R¹⁷ independently of one another denote C₁-C₈-alkylor phenyl, where R¹⁷ can additionally denote hydrogen or acyl, and R²⁰denotes phenyl or C₁-C₄-alkyl, or a nickel catalyst which can beprepared by reaction of a nickel(O) compound, or a compound which can beconverted in situ into a nickel(O) compound, with an adduct ofbenzoquinone or maleic anhydride and a phosphine of the formula

in which R¹⁵ and R¹⁶ have the meaning mentioned, and a compound of theformula (IV).
 4. The process of claim 1, wherein 0.01 to 100 mmol ofnickel catalyst are employed per mol of styrene derivative.
 5. Theprocess of claim 5, wherein 0.1 to 10 mmol of nickel catalyst areemployed per mol of styrene derivative.
 6. The process of claim 6,wherein 0.2 to 5 mmol of nickel catalyst are employed per mol of styrenederivative.
 7. The process of claim 1, wherein a styrene derivative ofthe formula

is employed in which R¹⁸ is hydrogen, C₁-C₄-alkyl, C₂-C₄-alkenyl,C₂-C₇-acyl, fluorine, chlorine or bromine and R¹⁹ is hydrogen,C₁-C₄-alkyl, vinyl or chlorine.
 8. The process of claim 8, wherein astyrene derivative of the formula

is employed in which R²⁸ is hydrogen, methyl, ethyl, i-butyl,C₂-C₇-acyl, vinyl or chlorine and R²⁹ is hydrogen, vinyl, methyl orchlorine.
 9. The process of claim 1, which is carried out at atemperature of 30° to 160° C.
 10. The process of claim 9, which iscarried out at a temperature of 40° to 120° C.
 11. The process of claim10, which is carried out at a temperature of 50° to 100° C.
 12. Astyrene derivative extended with ethylene and having a double bondremaining in the extension formed, of the formula

in which R ⁴⁸ is i-butyl or benzoyl, and m is an even number from 6 to204.
 13. A styrene derivative extended with ethylene and having a doublebond remaining in the extension formed, of the formula

in which R ⁴⁸ is vinyl, and


14. A derivative according to claim 12, wherein m is up to 64.